The present invention relates to the testing of cable harness assemblies having planar, multi-conductor cable terminated to insulation displacement contacts, insulation piercing contacts, or the like housed in connectors. Such cable assemblies, their manufacture and testing are disclosed in U.S. Pat. Nos. 4,110,880 and 4,285,118 which issued to Peppler, et al., on Sep. 5, 1978 and Aug. 25, 1981 respectively and U.S. Pat. Nos. 4,870,752 and 4,903,403 which issued to Brown, et al., on Oct. 3, 1989 and Feb. 27, 1990 respectively, these patents being incorporated by reference as though set forth verbatim herein. The two Peppler, et al. patents disclose a cable harness making machine that performs an electrical test of the conductive paths for shorts and opens. A manually operable switch is provided for indicating the number of conductors in the cable. The two Brown, et al. patents disclose a cable harness making machine that performs electrical testing for shorts and opens at various stages of manufacture of the harness so that a connector will not be inadvertently terminated to a partially completed harness assembly that is defective. In all of these cases the electrical probes that connect the contacts of the connectors to the testing circuit are elongated conductors spring biased into contact with the individual connector contacts. The elongated conductors are of cylindrical shape and telescope into a tube containing a compression spring. Such probes are somewhat bulky and are therefore limited to applications where the individual connector contacts have substantial space surrounding them. Additionally, such probes engage the connector contacts by means of an abutting action rather than a wiping action, the latter being preferably because the contacting surfaces are wiped clean. In the event that the probes engage a surface of a connector contact that is angled with respect to the direction of movement of the probe, the probe has a tendency to bind in its tube making it difficult or impossible to insert the connector into the machine.
What is needed is an electrical test probe that can be spaced close enough to engage the closely spaced contacts of miniature connectors such as the modular plug. The probe should be able to move into and out of electrical engagement with the connector contact without binding and should provide a wiping action to assure good electrical contact.